Abstract: Various enhancements to grid-interactive inverters in accordance with embodiments of the invention are disclosed. One embodiment includes input terminals configured to receive a direct current, output terminals configured to provide an alternating output current to the utility grid, a controller, an output current sensor, and a DC-AC inverter stage comprising a plurality of switches controlled by control signals generated by the controller. In addition, the controller is configured to: generate control signals that cause the switches in the DC-AC inverter stage to switch a direct current in a bidirectional manner; measure the alternating output current; perform frequency decomposition of the output current; and generate control signals that cause the switches in the DC-AC inverter stage to switch current in a way that the magnitude of a plurality of unwanted current components is subtracted from the resulting output current.

Abstract: Methods for measuring insulation resistance in a photovoltaic (PV) array may include partitioning the PV array into groups of PV panels, isolating a group of PV panels selected for an insulation resistance measurement from other groups of panels by setting bypass selectors on each PV panel in the PV array, and making an insulation resistance measurement for the selected group. If a measured value of insulation resistance for a selected group corresponds to an insulation problem in a PV array component, a separate measurement of insulation resistance may be made for each PV panel in the selected group. Insulation resistance measurements may be made accurately and rapidly for large PV arrays without disconnecting and reconnecting cables between panels. Measurements may be made at frequent, regular intervals to permit changes in insulation resistance to be detected before damage from dielectric breakdown occurs.

Abstract: A method for tracking a power point for a power source includes calculating voltage and current errors for the power source, selecting either the voltage error or the current error, and controlling the power converter with a first control loop in response to the selected error. The voltage and current errors may be calculated in response to voltage and current targets, respectively, which may be calculated by a second control loop that implements an MPPT algorithm. The second control loop may calculate the voltage and current targets in response to which error the first control loop selects. A method for tracking a power point for a power source having multiple local power maxima includes measuring the individual voltage across one or more series-connected power elements in the power source, and controlling the power in response to the overall voltage and current as well as the individual voltage.

Abstract: A control circuit according to an embodiment of the present invention for a DC-DC converter which has an input, an output and a series connection of a differentiator, a comparator unit, and an integrator. The series connection is coupled in between the input and the output. The comparator unit has an inverting amplifier.

Abstract: A method and apparatus for indicating a disconnection within a Distributed Generator (DG). In one embodiment, the apparatus comprises an alarm module electrically coupled to a conductive portion of a component within the DG, wherein the conductive portion is grounded via a ground rod system, and wherein the alarm module (i) is further coupled to a ground line, (ii) couples a monitoring current to the conductive portion, (iii) monitors flow of the monitoring current to determine a change in the flow, and (iv) generates, as a result of the change in the flow, a notification of the disconnection.

Abstract: The present invention provides a DC to AC converter including a device enabling separation of electric current into a positive portion of the circuit and a negative portion of the circuit, each portion of the circuit including an electronic switch, wherein one portion of the circuit is adapted to produce a wave form in a positive half cycle, the second portion of the circuit is adapted to produce a wave form in a negative half cycle, the voltage of the output current is fed to a polarity switch as feedback to change the polarity, and wherein the carrier duty cycle is adapted to change from 0 to 100 percent in each polarity.

Abstract: A grid-connected energy storage system capable of increasing the efficiency of a converter and a method of controlling the system are disclosed. In one aspect, the system includes a plurality of converters for converting power generated by each of the plurality of power generation modules into DC power at a voltage level, a plurality of series switches connected to the plurality of power generation modules, and a plurality of parallel switches configured to selectively connect each of the power generation modules to each and every other of the power generation modules. The system also includes a controller configured to control the switches in order to selectively connect each of the power generation modules to at least one selected converter.

Abstract: A method and apparatus of tracking the maximum power point of a photovoltaic module. The method includes measuring an output voltage of the photovoltaic module, determining an output voltage of the inverter connected to the photovoltaic module, and measuring output current of the inverter connected to the photovoltaic module. A variable relating to energy of the capacitor is defined using the measured PV module output voltage, and a second harmonic component is extracted from the defined variable. A second harmonic component of the module output power is estimated using the defined variable, measured output current of the inverter, and the determined output voltage of the inverter. The estimated and extracted second harmonic components are multiplied, and a DC component is extracted from the product. A control signal for controlling the inverter connected to the photovoltaic module is formed by using the extracted DC component in a PI algorithm.

Abstract: A power transfer system provides power factor conditioning of the generated power. Power is received from a local power source, converted to usable AC power, and the power factor is conditioned to a desired value. The desired value may be a power factor at or near unity, or the desired power factor may be in response to conditions of the power grid, a tariff established, and/or determinations made remotely to the local power source. Many sources and power transfer systems can be put together and controlled as a power source farm to deliver power to the grid having a specific power factor characteristic. The farm may be a grouping of multiple local customer premises. AC power can also be conditioned prior to use by an AC to DC power supply for more efficient DC power conversion.

Abstract: A method of controlling a photovoltaic system includes providing a photovoltaic device having a variable DC voltage output and a variable DC current output. The photovoltaic device has a combination of a voltage output level and a current output level corresponding to a maximum power point. A DC power supply is connected in a parallel and/or series combination with the photovoltaic device. A DC load is connected in series to the combination of the DC power supply and the photovoltaic device such that the load is powered by the combination. A characteristic of the DC power supply is adjusted such that the voltage output and the current output of the photovoltaic device substantially match the voltage output level and the current output level corresponding to the maximum power point or other desired power point.

Abstract: We describe a photovoltaic (PV) power generation system comprising at least two PV panels and a power conditioning unit. The dc power outputs of the PV panels are connected in parallel to a dc power input of the power conditioning unit. The power conditioning unit comprises a dc-to-dc converter having an input coupled to the dc power input and an output coupled to a dc link of the unit, a dc-to-ac converter having an input coupled to the dc link and an ac mains power supply output, and an energy storage capacitor coupled to the dc link. The power conditioning unit is configured to perform maximum power point tracking (MPPT) responsive to a level of power flowing into the dc power input, and the level of power flowing into said dc power input is sensed at the dc link. In preferred implementations the energy storage capacitor is a non-electrolytic capacitor.

Abstract: Provided is a maximum power point (MPP) tracker for a PV cell inverter, and a PV cell inverter. The MPP tracker decouples output power oscillations from the input power generation and extracts maximum available power from the PV cell. The PV cell inverter uses the MPP tracker and generates a sinusoidal output current from the MPP tracker output. The sinusoidal output current may be fed to a power distribution grid. The PV cell inverter may use a pulse width modulation technique to cancel harmonics in the sinusoidal output current. The circuits use a minimum number of components and avoid use of large electrolytic capacitors.

Abstract: The present invention, a modified zero voltage transition (ZVT) full bridge converter, is an isolated dc/dc converter which can operate with high efficiency and high reliability in applications requiring a low input voltage and high output voltage.

Abstract: A standalone solar energy conversion system includes a first DC-DC conversion apparatus, a second DC-DC conversion apparatus, and a control apparatus. The first DC-DC conversion apparatus receives a DC voltage and converts a voltage level of the DC voltage to provide a capacitance voltage. The second DC-DC conversion apparatus receives the capacitance voltage and converts a voltage level of the capacitance voltage. The control apparatus includes a first comparison unit and a second comparison unit. The capacitance voltage is compared to a first capacitance voltage command and a second capacitance voltage command through the first comparison unit and the second comparison unit, respectively, thus controlling output powers of the first DC-DC conversion apparatus and the second DC-DC conversion apparatus.

Abstract: A discontinuous conduction current mode maximum power limitation photovoltaic converter connects to a ground and a solar cell having a temperature compensation signal and an output power and being solarized and includes a direct current/direct current voltage converter and a maximum power control circuit. The direct current/direct current voltage converter connects to the solar cell, includes an input terminal and an output terminal, offers a stable voltage and has an output voltage signal and an inner current. The maximum power control circuit connects to the direct current/direct current voltage converter and the solar cell, controls the direct current/direct current voltage converter to limit the output power of the solar cell to maximum and includes a temperature compensation feedback circuit, an output voltage feedback circuit, a current detection circuit and a main control circuit.

Abstract: A photovoltaic system for generating an output voltage that is uninfluenced by varying irradiation, includes a photovoltaic source having an input terminal and an output terminal. The photovoltaic system includes a voltage adding arrangement having a first input terminal and an output terminal. The voltage adding arrangement is connected in series with the photovoltaic source, and includes a first route having a voltage source and a second route as a voltage source bypass. The first and second routes extend between the first input terminal and the output terminal of the voltage adding arrangement. The first and second routes being alternately activateable.

Abstract: A method for manufacturing a solar concentrator cell module assembly within an integrated circuit process, which solar concentrator cell module assembly includes at least one solar device and which solar device includes one printed circuit board and one Fresnel lens. A printed circuit board is assembled according to a pre-defined circuit board base design layout that allows pick and place of a single solar concentrator cell chip onto a circuit board base. Connections are provided for the solar concentrator cell chip in a serialized or a parallelized arrangement on the circuit board base, and a plurality of openings are formed in the circuit board base below a backside of the solar concentrator chip to enable attachment of cooling fingers.

Abstract: A battery charger, or charge controller, for a photovoltaic system is disclosed, comprising a maximum power point tracker (MPPT) circuit, which may be bypassed by means of a bypass circuit. The bypass circuit may be a simple electrical wire or link. The battery charger is operable to track the maximum power of a photogenerator by means of the MPPT, or to bypass the MPPT and disable it, in dependence on whether the power loss which results from the MPPT would be greater than the power saving achieved by tracking the maximum power point of the photogenerator. Also disclosed is a control unit for use in such a battery charger, and a method for controlling such a battery charger.

Abstract: Exemplary embodiments of the disclosure relates to a photovoltaic system for generating an output voltage which is uninfluenced by varying irradiation. The photovoltaic system includes at least one photovoltaic unit having two photovoltaic sources, wherein each photovoltaic source includes an input terminal and an output terminal. The photovoltaic unit includes two voltage adding arrangements, each voltage adding arrangement having a first route including a voltage source and a second route including a voltage source bypass. The first voltage adding arrangement is connected in series with the first photovoltaic source and the second voltage adding arrangement is connected in series with the second photovoltaic source. A switch is arranged between an input terminal of the first photovoltaic source and an output terminal of the second photovoltaic source.

Abstract: Power generated by a solar battery of thin-film type is stepped up to a predetermined DC voltage by a step-up chopper circuit, and the predetermined DC voltage is converted into three-phase AC power by an inverter circuit, and the three-phase AC power is supplied to an AC power supply system via an output DC voltage circuit. The solar battery is not grounded, and a negative electrode thereof has a floating capacitance between the negative electrode and the ground. The AC power supply system is configured by three-phase star-connection, and the neutral point is grounded. The output DC voltage circuit includes three batteries, and the batteries are provided, for the respective phases, between the AC power supply system and a sine wave filter connected to the AC output side of the inverter circuit. Therefore, it is possible to prevent acceleration of the deterioration of the solar battery.

Abstract: Provided are a solar energy generation system having an adaptive maximum power point tracking function and a method thereof. The solar energy generation system includes: a minimum maintenance voltage determination unit configured to output a minimum maintenance voltage which enables the inverter to maintain an operation thereof corresponding to a grid voltage of the grid; a maximum power point tracking controller configured to determine a maximum power point tracking voltage at a maximum power point of the photovoltaic module, using the minimum maintenance voltage and an output voltage and output current of the photovoltaic module, and to output a reference voltage to track the maximum power point; a voltage calculator configured to calculate a difference between the reference voltage and the output voltage of the photovoltaic module; and a voltage adjuster configured to generate a reference current value using an output of the voltage calculator.

Abstract: A method for controlling an multi-stage inverter comprises controlling an input converter of the multi-stage inverter with an input controller and controlling an output converter of the multi-stage inverter with an output controller separate from the input controller. The input controller and output controller may be galvanically isolated. Additionally, the method may include communicating data between the input controller and the output controller over a power bus of the multi-stage inverter.

Abstract: An apparatus, device, and system for generating an amount of output power in response to a direct current (DC) power input includes a configurable power supply, which may be electrically coupled to the DC power input. The configurable power supply is selectively configurable between multiple circuit topologies to generate various DC power outputs and/or and AC power output. The system may also include one or more DC power electronic accessories, such as DC-to-DC power converters, and/or one or more AC power electronic accessories such as DC-to-AC power converters. The power electronic accessories are couplable to the configurable power supply to receive the corresponding DC or AC power output of the configurable power supply.

Abstract: A power inverter system includes a plurality of power semiconductor switching devices. Each switching device includes a corresponding gate turn off resistance configured to increase during starting up periods of the inverter system such that the open circuit voltage of a corresponding power source providing power to the power inverter system does not exceed the switching device blocking voltage ratings during the corresponding switching turn-off periods. The starting up period is the time required to bring the corresponding power source voltage from its open circuit voltage level to a predetermined voltage which constitutes a safe operating condition for the plurality of power semiconductor switching devices.

Abstract: A converter circuit includes first and second input terminals, first and second capacitors, the second capacitor having a first terminal connected to the second input terminal and a second terminal forming a positive voltage node, first and third semiconductor components connected in series between the first input terminal and the positive voltage node, the midpoint between the series connection forming a first node, and a series connection of a first inductive component, a diode and a second inductive component. The series connection is connected between the second input terminal and the node. The diode's polarity allows current to pass from the direction of the second input terminal. A second node is formed between the first inductive component and the diode, and a third node is formed between the diode and the second inductive component. A third capacitor is connected between the first input terminal and the third node.

Abstract: A power system includes a plurality of DC/DC converters and a DC/AC inverter. The plurality of DC/DC converters having outputs electrically connected in parallel for supplying a DC voltage bus to an input of the DC/AC inverter. The plurality of DC/DC converters each include a maximum power point tracker (MPPT). Various DC/DC converters and DC/AC inverters suitable for use in this system and others are also disclosed.

Abstract: A voltage limiter device of an assembly of photovoltaic modules, including: (a) means (Z1) forming an electronic switch for a current of said assembly; (b) comparison means (Comp, R1, R2, C2) for comparing a voltage at the output of the limiter with a reference voltage value (Vref); and (c) means for controlling the means forming an electronic switch, depending on the result of the comparison carried out by the comparison means.

Abstract: A power conditioner that suppresses generation of voltage spikes in a part of a generated sinusoidal voltage waveform. An offset between the timing of chopping, which depends on whether the voltage difference between the voltage of a third pulse voltage series and a sinusoidal voltage is positive or negative, and the timing of the switching between on/off duty cycles of a seventh and eighth switch is calculated, and the on/off duty cycles of the seventh and eighth switches are controlled on the basis of the timing offset.

Abstract: A power converting apparatus is provided with a step-up chopper circuit (2) that steps-up an input voltage (Vi) from a distributed power supply, an inverter circuit (3) that converts the output voltage (Vd) of the step-up chopper circuit (2) into alternating current, a first control circuit for controlling the output voltage (Vd), and a second control circuit for controlling the chopper input current (Ii). The first control circuit generates a target current value (Ir) so as to make the output voltage (Vd) become a target output voltage value (Vr). The second control circuit controls the step-up chopper circuit (2) so as to make the chopper input current (Ii) become the target current value (Ir). The first control circuit also has a low-pass filter (23a) that removes ripple components included in the output voltage (Vd).

Abstract: A method is described wherein DC power is converted into battery charging power by means of an inductor carrying a current which is controlled by a power controller during an adjustable part of a pulse width period. The pulse width period is made adjustable in order to influence the power consumption of the controller which consumes a substantial amount of the total power consumed for controlled DC-DC conversion. Several additional features are provided to improve the efficiency and to further reduce the power consumed by both the converter and the power controller, which provides new uses for a variety of products and appliances having solar cells, such as road studs.

Abstract: A converter system comprises a DC to AC converter, a maximum power point tracking device, and an array-side control. The DC link converts DC from a photovoltaic array to AC for a grid. The maximum power point tracking device is coupled to the array. The array-side control, which is coupled to the DC to AC converter and the device, prevents overvoltage in the DC bus of the DC to AC converter using array voltage and current data from the device and DC bus voltage data from the DC to AC converter during a grid transient by adjusting a maximum power point of the array to increase array voltage.

Abstract: A power converting apparatus comprises a DC-DC converter circuit that steps up or steps down an input voltage from a DC power supply, a DC-AC converter circuit that converts an intermediate voltage outputted by the DC-DC converter circuit to an alternate current, and a control circuit that controls the DC-DC converter circuit and the DC-AC converter circuit. The control circuit is provided with a circuit control unit that controls the DC-DC converter circuit so that the modulation factor, which is the amplitude ratio between a signal wave for manipulating the DC-AC converter circuit and the carrier wave therefor, will become a target modulation factor.

Abstract: A sequential switching shunt regulator cell comprising: a power line (PL) for connecting a power source (SA) to a power bus (PB); a shunting (SSW) switch for shunting said power line; and driving means (DM) for opening or closing said shunting switch depending on an error signal (MEA) indicative of a voltage level of said power bus; characterized in that it also comprises: a non-redundant rectifier (D3) connected in series to said power line for disconnecting the power bus from the shunting switch when the latter is closed; and a fault detector (FD) for detecting a short-circuit fault condition of said non-redundant rectifier, and for opening the shunting switch in reply to said condition. Advantageously, the rectifier can be a synchronous rectifier. A solar power regulator comprising a plurality of solar arrays connected to a power bus through respective sequential switching shunt regulator cells of the kind described above.

Abstract: According to one embodiment, an apparatus includes a controller which outputs a signal for controlling ON and OFF of a switch which changes over connection between a second input terminal and the output end of a coil. The controller includes an MPPT control unit which follows a maximum power point with a period based on a zero-cross detection signal of a system voltage based on an input signal acquired by subtracting a value obtained by multiplying a droop gain simulating drooping characteristics, a control unit which outputs a direction value in such a manner that a difference between a reference output from the MPPT control unit and the input signal becomes zero, and a PWM comparator which outputs a PWM signal based on the direction value and a triangular wave voltage.

Abstract: There is provided an apparatus and method for controlling a switch of a flyback converter for a solar generating system. The apparatus for controlling a switch of a flyback converter for a solar generating system includes: an MPPT controller generating a current command value for a maximum power point tracker of a solar cell module, based on input voltage, input current, and output voltage of the flyback converter; a current controller generating a current control signal for tracking the current command value; an output current command value generator generating the phase and magnitude command value of the output current, based on the phase of the output voltage and the current control signal; and a switch controller controlling the main switch of the flyback converter, based on the phase and magnitude command value of the output current, thereby simplifying a circuit while solving disadvantages of a discontinuous conduction mode and a boundary conduction mode.

Abstract: There are provided a method and an apparatus for generating a current command value for tracking the maximum power point of a solar energy generating system. The apparatus includes: a voltage detector detecting a voltage input into the flyback power converter; a first calculator calculating an output power from the detected input voltage; a second calculator calculating a power variation based on the calculated output power and a voltage variation of the input voltage; and a current command value generator generating a current command value for tracking the maximum power point of the solar cell module from the calculated voltage variation and the calculated power variation. Accordingly, a current command value after calculating an output power may be generated with only a voltage detector, without a current detector, thereby reducing the costs of a solar energy generating system by decreasing the costs for a high-priced current detector, and simplifying circuit.

Abstract: Exemplary systems and methods provide a transformer-isolated current-fed quadratic full-bridge converter topology. The optimal interfacing of a current source, such as a solar panel, can be implemented by using current-fed converters. The current-fed converter can operate within the whole range of a UI curve from short-circuit to open-circuit condition and its input voltage can be readily controlled. The quadratic behaviour between input and output in regard of a duty cycle allows large conversion ratios.

Abstract: The present invention discloses a power conversion circuit. A control module controls a pulse width modulation regulator to regulate a duty cycle of a DC-DC converter according to the direct current link voltage of the DC-DC converter and the output current and voltage of a renewable power supply. The control module also controls the pulse width modulation regulator to regulate a duty cycle of a DC-AC inverter according to the direct current link voltage of the DC-DC converter, output voltage of a utility power supply, and the output current and voltage of the renewable power supply.

Abstract: An organic dye used in a dye-sensitized solar cell is described, having general formula (1): wherein Ar1 represents a substituted or unsubstituted arylene group, Ar2 and Ar3 each independently represent a substituted or unsubstituted aryl group, Sp1 represent a single bond or a spacer group allowing conjugation between Ar1 and the furan moiety, Sp2 represent a single bond or a spacer group allowing conjugation between the furan moiety and Ac, Ac represents an acceptor group, and Y represents an anchoring group.

Abstract: The present invention relates to a power conditioning unit for delivering power from a dc power source to an ac output, particularly ac voltages greater than 50 volts, either for connecting directly to a grid utility supply, or for powering mains devices independent from the mains utility supply. We describe a power conditioning unit for delivering power from a dc power source to an ac mains output, the power conditioning unit comprising an input for receiving power from said dc power source, an output for delivering ac power, an energy storage capacitor, a dc-to-dc converter having an input connection coupled to said input and an output connection coupled to the energy storage capacitor, and a dc-to-ac converter having an input connection coupled to said energy storage capacitor and an output connection coupled to said output, wherein said energy storage capacitor has a capacitance of less than twenty microfarads.

Abstract: Reliability enhanced systems are shown where an short-lived electrolytic capacitor can be replaced by a much smaller, perhaps film type, longer-lived capacitor to be implemented in circuits for power factor correction, solar power conversion, or otherwise to achieve DC voltage smoothing with circuitry that has solar photovoltaic source (1) a DC photovoltaic input (2) internal to a device (3) and uses an enhanced DC-DC power converter (4) to provide a smoothed DC output (6) with capacitor substitution circuitry (14) that may include interim signal circuitry (28) that creates a large voltage variation for a replaced capacitor (16). Switchmode designs may include first and second switch elements (17) and (18) and an alternative path controller (21) that operates a boost controller (22) and a buck controller (23) perhaps with a switch duty cycle controller (32).

Abstract: Methods, apparatus and media for controlling a switching circuit controlling an amount of power drawn from an energy converter, to optimize the amount of power drawn from the energy converter. An output voltage and an output current of the energy converter are measured to produce signals representing converter output voltage and current. Converter power is calculated from the product of the converter output voltage and current. A perturb voltage is calculated as a decreasing nonlinear function of the converter power. A new reference voltage signal representing a desired converter output voltage is produced in response to a previous reference voltage signal and the perturb voltage. The reference voltage signal is used by the switching circuit to adjust the power drawn from the converter to achieve the desired converter output voltage.

Abstract: An apparatus and method for extracting maximum power from a solar cell are provided. The apparatus includes a solar cell for producing power from solar energy, a maximum power extractor for generating a pulse width modulation signal for extracting the maximum power from the solar cell, and a DC-DC converter for adjusting an amount of current generated from the solar cell according to the pulse width modulation signal.

Abstract: A power storage system and a method of controlling the same include supplying power to a load by connecting a power generation system and a grid. The system includes a power converting unit that operates in one of at least two control modes including a maximum power point tracking control mode in which the power generation system is controlled to generate maximum power and a voltage control mode in which a boosting ratio is adjusted according to a change in the amount of power consumed by a load. The system also includes a direct current (DC)/DC converter for converting an output voltage of the power converting unit into a DC link voltage, an inverter for converting the DC link voltage into an alternating current (AC) voltage appropriate for the grid, and a central controller for controlling operations of the power converting unit, the DC/DC converter, and the inverter.

Abstract: A microinverter is provided for converting DC energy from a PV panel into a grid-compatible AC signal. A first plurality of switching elements is coupled between a DC energy source and a primary winding of a transformer. A second plurality of switching elements is coupled to a secondary winding of the transformer. Current sensors sense real time converter parameters including a DC input, an AC output, and a primary current. A digital controller determines an operating mode for the converter based on a DC input signal, with the controller further including a switch signal generator circuit configured to adjust switching states. The switch state adjustments are based on the operating mode, real time converter parameters which include the DC input signal, an AC signal for output to a grid, a primary current, and a desired shape for the AC output signal waveform.

Abstract: In one exemplary embodiment, a control circuit includes a comparator circuit that compares a solar cell voltage and a battery voltage and responsively activates a charging control signal if the solar cell voltage is greater than the battery voltage. If the solar cell voltage is not greater than the battery voltage, the comparator circuit deactivates the charging control signal.

Abstract: A solar wind chime includes a chime and a striker suspended from a body. A solar energy system is carried by the body and includes a solar energy collection system configured to recharge a rechargeable electrical power source. An electrical subsystem conductively couples to the rechargeable electrical power source.

Abstract: Disclosed are a maximum power point tracker, a power conversion controller, a power conversion device having an insulating structure, and a method for tracking maximum power point. The power conversion device includes: a DC/AC converter including a primary DC chopper unit having a primary switch, a transformer, and an AC/AC conversion unit including a secondary switch; a current detector detecting current from an input stage of the DC/AC converter and providing a detected current value; a voltage detector detecting a system voltage from an output stage of the DC/AC converter; and a power conversion controller generating a primary PWM signal to be provided to the primary DC chopper unit and secondary first and second PWM signals, having the mutually opposing phases, to be provided to the AC/AC conversion unit by using the detected current value and the system voltage.

Abstract: We describe a power conditioning unit with maximum power point tracking (MPPT) for a dc power source, in particular a photovoltaic panel. A power injection control block has a sense input coupled to an energy storage capacitor on a dc link and controls a dc-to-ac converter to control the injected mains power. The power injection control block tracks the maximum power point by measuring a signal on the dc link which depends on the power drawn from the dc power source, and thus there is no need to measure the dc voltage and current from the dc source. In embodiments the signal is a ripple voltage level and the power injection control block controls an amplitude of an ac current output such that an amount of power transferred to the grid mains is dependent on an amplitude of a sinusoidal voltage component on the energy storage capacitor.

Abstract: A method for the selective doping of silicon of a silicon substrate (1) for producing a pn-junction in the silicon is characterized by the following steps: a) Providing the surface of the silicon substrate (1) with a doping agent (2) based on phosphorous, b) heating the silicon substrate (1) for creating a phosphorous silicate glass (2) on the surface of the silicon, wherein phosphorous diffuses into the silicon as a first doping (3), c) applying a mask (4) on the phosphorous silicate glass (2), covering the regions (5) that are later highly doped, d) removing the phosphorous silicate glass (2) in the non-masked regions, e) removing the mask (4) from the phosphorous silicate glass (2), f) again heating for the further diffusion of phosphorous from the phosphorous silicate glass (2) into the silicon as a second doping for creating the highly doped regions (5), g); complete removal of the phosphorous silicate glass (2) from the silicon.